Validity and Reliability of the Turkish Version of Mandibular Function Impairment Questionnaire

Objective To assess the validity and reliability of the Turkish version of the Mandibular Function Impairment Questionnaire (MFIQ-TR). Methods Included in this study were 248 patients diagnosed with temporomandibular disorder (TMD) according to Diagnostic Criteria for TMD Axis I protocol. Construct-related validity was evaluated through internal and external construct validity; convergent and divergent validities were evaluated by the average variance extracted (AVE), composite reliability (CR), and bivariate correlations between factors. Reliability was assessed by internal consistency and test-retest reliability. Results All items of the MFIQ-TR had content validity and factor loadings above 0.5. The model statistics indicated a good fit. The convergent validity was very good (AVE > 0.5 and CR > 0.7), and the discriminant validity was satisfied. Internal consistency and test-retest reliability of the MFIQ-TR were excellent. Conclusion The MFIQ-TR is a valid and reliable instrument for evaluating the impairment of mandibular function in Turkish patients with TMD.